Co-pending U.S. patent application Ser. No. 516,622 to Yang, et al., filed July 25, 1983, and assigned to common assignee, discloses a mechanical fastening system for securing a flexible sheet within a channel member via an insert member wherein the latter is made of a flexible resilient material having a central longitudinal flex notch that serves to define two adjacent wing portions and permits a temporary elastic deformation of the insert member into an inverted V-shape for insertion of the insert member, together with adjacent portions of the flexible sheet, into the channel member. In the interest of full disclosure, this application is incorporated herein by reference to the extent necessary to explain this particular mechanical fastening system.
Co-pending U.S. patent application Ser. No. 516,618 to Yang, et al., filed July 25, 1983 and assigned to common assignee, discloses a further attachment device for securing flexible sheets within a channel member via an insert member of generally inverted V-shape wherein the latter is made of a ductile but rigid material having a central longitudinal material portion of reduced rigidity that serves to define two adjacent wing portions and permits the subsequent plastic deformation of the insert member into its installed shape after its insertion, together with adjacent portions of the flexible sheet, into the channel member. Again, in the interest of full disclosure, this application is incorporated herein by reference to the extent necessary to explain this particular attachment device.
In both the previously-noted mechanical fastening system and attachment device, preferably metallic channel members are utilized to produce long tracks, with these tracks having ends, which are either factory cuts or field end cuts. The channel members must initially be adhered to a substrate and the system, to a large extent, relies substantially on the skillfulness of a roofer for providing the proper vertical and horizontal alignment between succeeding channel members as well as providing adequate expansion gaps therebetween. This application method has proven both too time-consuming and too dependent upon individual skills. Misalignment during installation may cause occasional flexible sheet or membrane damage via cutting or tearing at channel ends. Pinching of the membrane between adjacent channel ends, due to inadequate expansion gaps therebetween, can also result in premature membrane failure.